This invention relates generally to disc drives and more particularly, but not by way of limitation, to disc drive actuators.
Computers geared towards all sorts of uses commonly use hard disc drives to store large amounts of data in a form that can be readily accessed by a user. A hard disc drive generally includes a stack of vertically spaced magnetic discs that are rotated at a constant high speed by a spindle motor. The surface of each disc is divided into a series of concentric, radially spaced data tracks in which the data are stored in the form of magnetic flux transitions.
Data is stored and accessed on the discs by an array of read/write heads (xe2x80x9cheadsxe2x80x9d) mounted to a rotary actuator assembly or an xe2x80x9cE-block.xe2x80x9d Typically, the E-Block includes a plurality of actuator arms that project outwardly from an actuator body to form a stack of vertically spaced actuator arms. The stacked discs and arms are configured so that the surfaces of the stacked discs are accessible to the heads mounted on the complementary stack of actuator arms.
Each of the heads is mounted to an actuator arm by a flexure that attaches to the end of the actuator arm. Each head includes an interactive element such as a magnetic transducer which either senses the magnetic transition on a selected data track to the read the data stored on the track, or transmits an electrical signal that induces magnetic transition on the selected data track to write data to the data track. Air currents are generated by the high-speed rotation of the planar surfaces of the discs. A slider assembly included on each head has an air bearing surface, which interacts with the air currents to cause the head to fly at a short distance above the data tracks on the disc surface.
As the disc drive industry has developed, the emphasis has been on increasing the amount of storage available in each individual drive. While there was a time where the mechanism used to accomplish this was to add more discs to the drive, recent developments have now turned to increasing the number of tracks per inch (TPI) on the disc itself as a method of increasing storage capacity of the drive.
Part of increasing the TPI of a drive is to provide a stable environment within the disc drive itself. Part of this stable environment includes minimizing the amount of turbulence created by the wind generated by the rotation of the discs in the drive. Any turbulence within the drive may generate vibrations in the actuator arm and unwanted movement of the supporting suspension and the head/gimbal assembly (HGA). The increased TPIs of discs today are less tolerant of any significant modulation of the head, as it increases the incidence of errors in both reading and writing data to the discs.
In the past, various methods have been utilized to reduce the amount of air turbulence in the drive. These methods have included the use of shrouds and air dams around the perimeter of the discs in a disc stack. Other methods have utilized modifications in the design of the actuator aim itself. For example, in one such configuration, a wedge shape is provided on the leading surface of the actuator arm. This configuration functions to decrease the amount of turbulence in the drive. However, this alternative method creates a laminar airflow downstream of the arm that can create a small number of high amplitude excitations upon the HGA. These excitations are created when the laminar airflow generated by the spinning of the discs flows in one laminar layer over the actuator arm. This large flow interacts with other airflows in the drive, namely those under and around the actuator arm, thus creating large amplitude excitations of the head. While turbulence in the drive is reduced, the large amplitude excitations can dramatically affect the ability of the head to not only stay on track, but also to write data on track. Therefore, there is a need for an improved technique for reducing air turbulence within the disc drive.
The present invention relates to a disc drive actuator arm having a contoured leading surface portion for reducing flow-induced disturbance action on the head.
In accordance with one embodiment of the invention, a disc drive assembly includes a basedeck and top cover. A spindle motor mounted to the basedeck which rotates around a central axis; at least one magnetic storage disc mounted to the spindle motor for rotation around the central axis and an actuator arm assembly. The actuator arm assembly includes an actuator arm rotatably attached to a pivot axis and a suspension arm attached to a distal end of the actuator arm. A magnetic transducing head is attached to the suspension. The head is used to read and write data to the magnetic storage disc. Finally, leading surface portion of the actuator arm utilizes several turbulence-reducing portions laterally recessed so as to guide an airflow to reduce a flow-induced disturbance acting on the transducing head.
A further embodiment of the invention may include the use of rounded notches distributed across the leading surface portion of the actuator arm. Yet another embodiment utilizes saw-toothed triangular cutouts on the leading surface portion of the actuator arm to divide the laminar airflow interacting with the actuator arm.
The present invention can also be implemented as an actuator assembly in a disc drive having at least one rotatable disc, the actuator assembly includes an actuator arm rotatably attached to a pivot axis and a suspension arm attached to a distal end of the actuator arm. A magnetic transducing head is attached to a distal end of the suspension and is used to read and write data to the disc. A leading surface portion of the actuator arm has several turbulence-reducing portions laterally recessed so as to guide an airflow to reduce flow-induced disturbance action on the transducing head.
These and various other features as well as advantages that characterize the present invention will be apparent upon reading of the following detailed description and review of the associated drawings.